Fluid take-off from turbine pump for cooling systems



R. A. RHODA 3,250,069

FLUID TAKE-OFF FROM TURBINE PUMP FOR COOLING SYSTEMS May 10, 1966 FiledNov. 4, 1965 q-L-V INVENTOR. RALPH A. RHODA FIG. .1.

ATTORNEYS United States Patent 3,250,069 FLUID TAKE-OFF FROM TURBINEPUMP F0 COOLING SYSTEMS I Ralph A. Rhoda, Berkeley, Calif., assignor toBerkeley Pump Company, Berkeley, Calif., a corporation of CaliforniaFiled Nov. 4, 1963, Ser. No. 321,035 4 Claims. (Cl. 60-355) Thisinvention relates to cooling systems for engines supplied with waterfrom the discharge end of a hydropump. The invention more particularlyinvolves the location and construction of a fluid take-off fromhydropumps through which large quantities of foreign material maypassduring normal usage.

Many conventional drive system for watercraft com-, prise a water-cooledengine that drives a turbine-type hydropump. The main discharge from thepump is used for propelling the watercraft, but a fluid take-oil. fromthe pumps discharge is commonly used for supplying water to acoolantmanifold of the engine. Because of the great quantity of foreignmaterial which may pass through the pump, it is necessary to separateout such material before piping the pumps discharge into the coolantmanifold. For this purpose, settling chambers and/ or filters arenormally used to'separate grit and other particles that might tend toclog the cooling system. While filtering arrangements of various kindshave been used with different success, each suffers from the commondisadvantage that frequent periodic cleaning is required.

vanes, and radially inward relative to the trailing edges of theimpeller vanes on the downstream side ,of the impeller. Thus, any fluid(and foreign material) which reaches the take-off opening must firstpass forward and radially inward. Because of the greater momentum offoreign material compared with the water, very little grit or sand findsits way into the neighboring region of the opening; and since thetake-off opening is located radially inward relative to outermost innersurface of the bowl, any material approaching the opening must have beencarried against the centrifugal force which normally holds the materialagainst the inside of the impeller bowl, which stream joins the maindischarge flow from the pump.

Various objects of this invention will become, apparent in view of thefollowing description and the accompanying drawings.

In the drawings forming a part of this application and in which likeparts are designated by like reference numerals throughout the same.

FIG. 1 is a side elevation of a power drive system including a turbinepump for propelling watercraft;

FIG. 2 is an enlarge section and detail taken on lines 22 of FIG. 1' andshowing the location and preferred construction of the fluid take-off;and

FIG. 3 is a section and detail taken on lines 3--3 of FIG. 2.

Referring to FIG. 1, there is illustrated a typical pumping system forpropelling a watercraft. (not shown). This system essentially comprisesa water-cooled engine 10 that drives a turbine pump 11 from which wateris conducted through a conduit 12 to the coolant manifold 13 of theengine. In the normal manner of operation, water 3,250,069 Patented 'May1 0, 1966 from beneath the watercraft is taken into the pump through abottom inlet 14. The water is then pressurized by the pump anddischarged from the end of an impeller bowl 15. A small portion of thepumped and pressurized fluid is also discharged into conduit 12 forcooling engine 10.

This invention is more particularly directed to the location of thepoint from which water is taken out of pump 11. .The importance of itslocation is that water fed through conduit 12 will contain very littlegrit or foreign material, although the main stream of the pump may, infact, contain a greatdeal. It is-to be recognized that the point ofwater take-off is of particular importance to a pumping system forpropelling watercraft because of the vast amounts of foreign materialthat are normally taken in and expelled during operation. With standardtake-offs, it is essential to employ sometype of filter, and thesefilters must be cleaned with great frequency and regularity.

Referring to FIG. 2, impeller bowl 15 comprises a twopart assembly of aseal housing 16 having a seal ring 17 and a main bowl housing 18. Thegeneral arrangement of this assembly, including the mounting of animpeller 19, is known, but the location of the take-01f passageway 20 isbelieved to be novel. More particularly, passageway 20 is formedcircumferentially of seal ring 17 in housing 16, and terminates with aninner inlet opening 21 located peripherally of and intermediate thetravelled paths of the leading edges 22 and trailing edges 23 ofimpeller vanes 24. Opening 21 is more particularly oriented so that thepassageway 20 is exposed radially and atva point radially inward ofimpeller vane edges 23.

It has been found that the greater density and momentum of foreignmaterial (compared with water) tends to keep it in the main flow stream,while only the water will travel forward relative to the trailing edge23 of vanes 24. In some instances, some small grains of sand may move toa position circumferentially of vanes 24, but the rotation of impeller19 will normally keep these grains in movement while centrifugal forceshold the grains against the inner surface of the impeller housing untilthey are returned to the main discharge stream. Further, since thetake-off opening 21 is only radially exposed to the interior of thehousing, and at a point radially inward relative to edges 23, anymaterial which passes in front of the opening must be carried againstthe centrifugal forces acting thereon. This fact alone insures that verylittle sand can reach opening 21.

FIG. 3 illustrates the preferred shape and location of opening 21relative to vanes 24. It will be seen that the mouth of opening 21includes a radial lead 21a that extends radially away from the innersurface of housing 16 but also in the direction opposite to impellerrotation, said lead terminating at an inner circular port 21b, the entryto passageway 20. Lead 21a is thus defined by a projection 25, whichextends radially inwardly as well as circumferentially relative to bowl15 and a relieved surface 26. The function of projection 25 is to shieldport 21b from any grains of sand as they are swirled about the innersurface and to force them radially away from said port. While somegrains of sand or foreign material may pass across and in front ofopening 21, the greater momentum of the grains will cause such materialto be bounced across from the surface of projection 25 to the surface26. At this point the grains will be carried back into the bowl.

It is to be understood that although a preferred embodiment of thisinvention has been shown and described, various changes may be madewithout departing from the spirit of the invention or the scope of theattached claims, and each of such changes is contemplated.

What I claim and desire to secure by Letters Patent is:

1. A water craftand propulsion unit comprising:

(a) a water-cooled engine mounted to said craft;

(b) a turbine pump mounted to said craft, said turbine pump comprising:i

(1) an impeller bowl having an inner circular seal located at the intakeend thereof;

(2) an impeller disposed within said bowl, said impeller having radialvanes extending into proximate relation to said inner seal and a shroudon the outer radial ends of said vanes, said shroud being supported forrotation by said inner seal and flaring radially outwardly from theleading edge of said vanes in proximate relation to said inner seal, tothe trailing edge of said vanes;

(3) said impeller bowl defining a fluid passageway extending radiallyoutward and circumferentially in a direction opposite to impellerrotation from the inner surface of said impeller bowl.

3. A water takeoff as set forth in claim 1 wherein the 5 opening of saidpassageway is radially shielded by a projection on the leading sidethereof relative to impeller rotation and is exposed radially andcircumferentially on the trailing side thereof by a relieved surface.

4. A water take-off as set forth in claim 1 wherein the opening of saidpassageway is located radially inward relative to the trailing edges ofsaid vanes.

References Cited by the Examiner UNITED STATES PATENTS 1,257,793 2/1918Bodinson 103-102. 1,500,607 7/1924 Conant l03l02 3,030,909 4/1962 Barneset al. 103-88 FOREIGN PATENTS 188,547 11/ 1922 Great Britain.

SAMUEL LEVINE, Primary Examiner.

HENRY F. RADUA ZO, Examiner.

1. A WATER CRAFT AND PROPULSION UNIT COMPRISING: (A) A WATER-COOLEDENGINE MOUNTED TO SAID CRAFT; (B) A TURBINE PUMP MOUNTED TO SAID CRAFT,SAID TURBINE PUMP COMPRISING: (1) AN IMPELLER BOWL HAVING AN INNERCIRCULAR SEAL LOCATED AT THE INTAKE END THEREOF; (2) AN IMPELLERDISPOSED WITHIN SAID BOWL, SAID IMPELLER HAVING RADIAL VANES EXTENDINGINTO PROXIMATE RELATION TO SAID INNER SEAL AND A SHROUD ON THE OUTERRADIAL ENS OF SAID VANES, SAID SHROUD BEING SUPPORTED FOR ROTATION BYSAID INNER SEAL AND FLARING RADIALLY OUTWARDLY FROM THE LEADING EDGE OFSAID VANES IN PROXIMATE RELATION TO SAID INNER SEAL, TO THE TRAILINGEDGE OF SAID VANES; (3) SAID IMPELLER BOWL DEFINING A FLUID PASSAGEWAYEXTENDING THERETHROUGH, SAID PASSAGEWAY OPENING INTO SAID BOWL AT APOINT ON THE DOWNSTREAM SIDE OF SAID INNER SEAL IN PROXIMATE RELATION TOSAID INNER SEAL AND SAID SHROUD, RADIALLY INWARDLY FROM SAID TRAILINGEDGES; AND (C) MEANS COMMUNICATION FROM SAID PASSAGEWAY TO SAIDWATER-COOLED ENGINE.